Comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex ® systems

Phosphorus (P) recovery through struvite is already both technically and economically feasible. This has been proved by more than 40 large-scale plants worldwide. However, when designing and implementing these P-recovery technologies, the environmental effects need to be considered. Therefore, a comparative environmental life cycle assessment of phosphorus recovery with different generations of the AirPrex ® reactors at WWTP Wassmannsdorf and Amsterdam West was carried out in this study. Results show that both AirPrex ® configurations with 1 reactor and 3 reactor have positive energy benefits and better environmental credits for the global warming potential (GWP), freshwater eutrophication potential, and marine eutrophication potential. The 3-reactor configuration shows better results in cumulative energy demand with 35% improvement of energy surplus, 36% reduction of GWP and less eutrophication potential. These improvements are mainly due to optimized struvite precipitation and harvesting and show that technology can be developed further, especially in plant operation and not only in the laboratory or pilot plant. Graphical Abstract